That's currently not supported.
Have a look at
clickable link widget and
Different colours in one string for two approaches that modify how fonts are rendered.
In your case you'd have to figure out the position from the left margin (multi-line support) and where the tabs need to be anchored at.
My
idea/thoughts on this matter
are that there is a need for
text markup to easily add support for various text attributes
within a string, much
like the strings we can generate here on the message board, such as what I was able to
create in this paragraph.
One approach could be to have a ScrollablePane parse a text string and generate DefaultText parts on the fly and properly lay them out.